At current, main synthetic methods of 2,6-dichloropyridine include: a gas phase photochlorination method of pyridine aqueous solution, in which an obtained main product is mixture of 2-chloropyridine and 2,6-dichloropyridine, the proportion of 2,6-dichloropyridine is generally 5%-50%, chloride materials need to be subjected to a series of steps, such as neutralization, crude distillation and rectification, to separate and purify 2,6-dichloropyridine, a great amount of wastewater and waste salt are produced, and the treatment cost of three wastes is high;
an ultraviolet-light-free direct-heating chlorination method of pyridine, in which the yield of 2,6-dichloropyridine is smaller than 30%, the coking rate is about 45%, a great amount of tar is produced and the treatment cost is high;
a liquid phase photochlorination method of 2-chloropyridine, in which the conversion rate of 2-chloropyridine is about 96% within 10 h and the yield of 2,6-dichloropyridine is about 93%, but there are some disadvantages such as blockage of tail gas pipeline by materials, the production process of the raw material 2-chloropyridine also causes the production of a great amount of wastewater and waste salt, and consequently the production cost is high.